Patent Literature 1 discloses a camera selecting device which selects a camera which has a field of view similar to a field of view of a viewer from a plurality of cameras. The device disclosed in Patent Literature 1 evaluates a relationship between positions and directions of point of views of the viewer and the camera, and selects a camera which has a field of view similar to the field of view of the viewer. More specifically, the device disclosed in Patent Literature 1 calculates an area of a triangle formed by a viewer's position P, a camera position and a point of view Q, and an angle formed between an optical axis center vector of the camera and a vector PQ. Further, the device disclosed in Patent Literature 1 selects a camera which has a field of view similar to the field of view of a viewer based on evaluation values of the area and the angle.
Furthermore, Patent Literature 2 discloses a position posture measuring method of calculating a position and a posture of one of two cameras using images captured by the two cameras of different resolutions.
Still further, Non Patent Literature 1 discloses a technique of calculating camera parameters based on an image obtained by a camera.